reMarkable tablet turned into Tom Riddle's diary; is it just a chat UI?

Write a question, pause, and watch the paper answer back

Maxime Rivest's Riddle turns a reMarkable Paper Pro into the enchanted diary from Harry Potter. You write on the page with the pen. When you stop, the page is committed as a PNG and handed to a vision-capable LLM, and the reply is drawn back as animated 'Dancing Script' handwriting that then fades: your words fade into the paper. There are two oracle backends, any OpenAI-compatible API or a resident local process for lower latency, and the easiest install is a single command; from source it's Rust for the app and C/C++ for the display layer. There is no demo video, an omission the thread called a criminal lack.

'Is this not just... a chat UI?'

Bob Nystrom, author of Crafting Interpreters, asked the question the demo invites:

No screen glow, no keyboard, no chat UI. Is this not just... a chat UI?

A self-described non-fan of the books put the dependency plainly:

I think you'd have to be a fan of the series to care as otherwise this is just a really slow chat interface.

A developer who had built the same thing first, in a browser with a local model, recognized the idea:

Amusingly, I made the same thing late last year, though just on an ordinary computer, allowing you to draw in the browser… After completing my experiment I learned I wasn't the first to think of this idea and found a few other similar AI Riddle diaries out there.

The sharpest note came from a growth-equity investor, on how tame the friendly version really is:

Ironically, Tom Riddle's diary encouraging kids to commit suicide and then showing them how to do it would be more on brand than the version in the books.

The joke lands because the diary in the books groomed a child into near-death; the charming build works by forgetting exactly that.